Tie continuity error.
Obvious, let’s call them “homages” to Hannibal Lecter movies – Red Dragon posing in front of the projected images, eyeballs and tongue in the jar. Benjamin Raspail’s head from “Silence…”.
Would anybody really be that stupid to not simply call the cops after seeing a murder and also really find it difficult to avoid being caught by the murderer when they’re both on foot? Banging on the teachers’ door instead of just calling it in and hiding quietly in the dark?
Luther amazingly able to jump his quarry in the maze of containers when the guy is on foot in the narrow bits but he’s in a car charging along the wide bit?
Turning on the tap after he’s switched on the kettle.
The police at HQ claiming the difficulty of pinpointing the suspect in “Hampstead Wood” whilst they’re actually looking at the pinpoint location of his phone whilst listening to him using it.
Suddenly being completely well just after he’s been punched in the ribs hard enough to at least fracture them.
Quite fancy the psychiatrist, though. Maximum quirk, there… 😳😉😜